Aeroplane-rudder construction



-F. J. PLYM.

AEROPLANE RUDDER CONSTRUCTION.

APPLICATION FILED 0m. 11, 1918.

1,335,527. I Patented 30,,1920.

Fray 9J2 77L,

nnron FRANCIS J. PLYM, OF NILES, MICHIGAN, ASSIGNOR TO KAWNEER MANUFACTURING COMPANY, OF NILES, MICHIGAN, A CORPORATION OF MICHIGAN.

AEROIIlANE-RUDDER CONSTRUCTION.

Specification of Iietters Patent.

Patented Mar. so, 1920.

Application filed October 11, 1918. Serial No. 257,780.

To all whom it may concern.-

Be it known that I, FRANCIS J. .PLYM, a citizen of the United States, residing at Niles, in the county of Berrien and State of hlichigan, have invented certain new and useful Improvements in Aeroplane-Rudder Construction, of which the following is a specification.

This invention relates to aeroplane rudders, and one of its objects is to produce 'a rudder in which the framework is of cellular construction and composed of metal. More specificallythe object is to produce a cellular rudder frame having camber and embodying skeleton built-up ribs which interlock at intersection points. A further object is to produce .ribs of the greatest strength and rigidity compatible with their weight. A still further objectis to produce a cellular metallic-frame rudder without welding and without the use of bolts and nuts or other fastening devices.

lVith these objects in view the invention consists in certain novel and useful features of construction and combinations of parts as hereinafter described and claimed; and in order that it may be fully understood reference is to be had to the accompanying drawing, in which:

Figure 1, is a perspective View of a rudder embodying my invention, the fabric covering being omitted.

Fig. 2, is an enlarged perspective view showing the construction of the ribs and the interlocking connection therefor.

In the said drawing, 1 indicates the hinge post or base tube of the rudder, and 2 the edging strip of the rudder frame, said edging strip being preferably in the form of a channeled metal strip curved to the desired contour and extending from the lower end of the base or hinge post to a polnt forward and downward with respect to the upper end thereof, the edging strip being rigidly secured in any suitable manner to the upper and lower ends of said tube. Parallel with the base tube or hinge post is a rib 3, and 4 designates a series of horizontal ribs which intersect the vertical rib 3 and are fastened to the same in a manner hereinafter ex plained. In this connection it will be understood that there may be more than one rib' the under-most rib 4L. 5-indicates a bracket secured in any suitable manner on" the base tube or post 1, at the front end of one of the horizontal ribs, and projecting from opposite sides of said bracket are the customary steering control arms 6.

Each rib tapers at its ends and is composed of channel bars 7 arranged with their channels facing each other, and metal strips 8 bent to zig-zag form fit between and into the channels of said bars and constitute a rigid skeleton bracing. The metal bracing strips are of width to fit snugly within the channels of bars 7, and at such points are formed with short portions 9, fitting flatly in and clamped to the bars by the adjacent portions of the flanges of the bars, that is .to say by portions of said flanges which are crimped or bent inward as at 10*. The braces are thus firmly interlocked with the bars without welding or the use of fastening devices. The operation of securing the braces to and between the bars 7 can be expeditiously performed by hand or otherwise.

Where ribs intersect, one of them is of slightly less depth than the other and eX- tends through thelatter, and the ribs being properly proportioned, they interlock with each other through the engagement of the one of less depth with notches produced in the inner side of the other'rib'by the crimp ing inward of itsflang'es at one of the points 10, as shown at theupper side of Fig. 2, and to guard against lateral shifting movement of the shallow rib upon the other rib, the underlying or companion bar 7 of thelatter, is provided with notches 11,- corresponding to the notches produced by crimping as described, though the notches 11,'maybe other-- wise produced.

By producing ribs of the construction described and arranging the ribs in intersecting relation, it is obvious that the rudder will possess the necessary camber which,

as far as applicant is aware, has only been produced heretofore in wood rudders, as it is practically impossible to provide camber in rudders made of steel tubing and the like, butted and welded together at the joints.

I have stated that the number of ribs may be varied, and it is likewise true that my construction is advantageous in that the ribs can be made any depth without materially increasing the weight, as would be the case if tubes were employed for the purpose.

From the above description it will be apparent that I have produced an aeroplane rudder embodying the features of'advantage set forth as desirable in the statement of the object of the invention, and while I have illustrated and described the preferred embodiment of the same, it will be apparent that it is susceptible of modification in various particulars Without departing from the principle of construction involved or the spirit and scope of the appended claims.

I claim: If 1. A rudder comprising a hinge post, a

' suitably contoured edging strip secured, to

the opposite ends of the post and provided with a channel at its inner side, a rib spanning the space inclosed by the post and edging stri and secured at its ends in the channel of t e latter, a plurality of ribs extending across and interlocked with the firstnamed rib; and with the edging strip and post, each rib consisting of strips having longitudinally extending channels facing each other, and zigzag strips interposed between the channel strips and engaging the channels thereof; the flanges of said strips where engaged byqsaid zigzag strips being crimped over upon the latter to secure them in position.

2. A builtup part for use in aeroplane construction composed of parts united at the ends and spaced apart intermediate the ends and channeled at their adjacent sides, and a zig-zag bracing strip between said parts and fitting against the same within the channels thereof; the flanges of the channeled parts being crimped over the bracing strip where the same contacts with said channel parts.

3. A built u part composed of oppositely bowed flange strips secured together at their ends, the channels of said strips facing inward toward each other, and a zigzag bracing strip between said parts and fitting against the same within the channels thereof,

bar receiving the adjacent bowed strips of the other bar in a notch formed by the crimping of the flanges of the first bar, the other bowed strip of the bar last referred to also having a notch in itsflanged edges receiving the other'bowed strip of the said second part.

In testimony whereof I affix my signature.

' FRANCIS J. PLYM. 

